The present invention is directed to a method for thermally fusing two mutually aligned optical fiber ends and to an apparatus for accomplishing the method.
Bringing together the fiber ends incipiently fused at their end faces can be particularly critical for producing a fused connection between the ends of the two optical fibers, which connection is acceptable as possible and, that is to say, to produce a fiber splice which has, as far as possible, the same cross-sectional geometry as is typical for the respective fiber throughout its entire remaining longitudinal length. Thus, for example, possible mispositioning of the fiber ends relative to one another leads to unacceptably high splice losses. A method by means of which it is possible to detect such mispositioning of two fiber ends to be fused in a fashion aligned flush with one another is disclosed in U.S. Pat. No. 5,011,259, whose disclosure is incorporated herein by reference thereto and which claims priority from the same German Application as European Patent No. 0 400 408. As disclosed, the two fiber ends are illuminated and an image thus produced of the fiber ends is scanned using an image sensor of a video camera. If the respective fibers have impermissibly high material deficits at the end faces, which can be caused, for example, by material vaporization, breaking-out of portions of the glass material, faults in the angular fracture or the like, it becomes yet more difficult for the fiber ends to be brought together and obtain an acceptable splice.